Most of us won’t find ourselves in a survival situation anytime soon, but you might feel pretty confident that you have what it takes to make it out alive. Do you really, though?

Picture yourself on a long, relaxing hike in the woods. Not your thing? Let’s try taking a swim at the beach during a family vacation. We all have these moments and, despite hearing numerous horror stories about the couple who got lost or the little girl that lost a leg to a shark bite, none of us ever picture it happening to us.

Even when the possibilities pop into our heads, we push them right back out, convincing ourselves we can handle it—after all, you can just punch a shark in the nose to make it let go, or play dead to make the bear go away, right?

Wrong. If you’ve never found yourself in a situation that required on any sort of survival knowledge to make it through, consider yourself lucky. In fact, if you believe any of these common survival myths, we’re willing to bet you wouldn’t have made it out alive.

The Myth: Punch Sharks in the Nose During Attacks

It’s a situation none of us ever hope to find ourselves in, but one that is entirely possible, though rare—being attacked by a shark while swimming or surfing in the ocean. For as long as we can remember, the key piece of advice in this situation has always been to try and punch the shark straight on its nose because it tends to be a fairly sensitive area for them. Unfortunately for us, though, there are a few problems with this tactic.

For one thing, it’d be incredibly hard to actually land a solid punch to a shark’s nose while you’re underwater, not only because of the resistance from the water, but also because the shark is probably moving.

Miss that punch and you could also end up driving your fist right into its mouth full of razor-sharp teeth, which just makes things worse for you.

Your best bet is to try and put something between yourself and the shark—a rock, some coral, your surfboard—but that isn’t always possible, depending on your surroundings. If you have to attack back, go for the eyes and gills first.

The Myth: Lost in the Woods? Find Food First

We occasionally hear of a camping trip gone bad, and in thinking of how to survive the situation, many of us think of one thing first—finding food. If you really want to survive, though, that’s not actually your best bet.

As it turns out, humans can actually survive for around 40 days without food, though a miserable 40 days they’d be.

Of course, this can vary based on the person themselves and the exact surroundings they’re in, but there are still two things that will always be more important than food in these situations—water and shelter. In harsh conditions, you might not even last for three hours without shelter, and you’d make it a mere three days tops without any water.

Oh, and you can also forget about the whole “moss only grows on the north side of a tree” thing to find your way out. Moss can grow anywhere on a tree, so don’t base your navigational decisions on it.

The Myth: Cactus Water Can Quench Your Thirst in the Desert

Speaking of finding water, many of us might think that a cactus would be our saving grace if we ever found ourselves lost in a desert. You just cut the plant open and drink any water you find stored inside to your heart’s content, right? You could do that, but you shouldn’t.

Cacti do contain stored water, and you could even eat the pulp of certain types if you really needed to, although it wouldn’t taste good. However, what most people don’t know is that cacti produce something called oxalic acid as a byproduct of photosynthesis, and this acid is actually toxic to humans.

When ingested, it binds with calcium and can eventually produce kidney stones, which is obviously the last thing you’d want to deal with while surviving in the desert. The toxins can also cause diarrhea and vomiting, which will only make you more dehydrated in the hot climate. If you truly needed to turn to a cactus for water, you’d have to drink it very carefully, as things could easily take a turn for the worse with too much.

Your best bet is to try digging to find stored water underneath the ground, checking under rocks for puddles of water, and eating cactus fruits or pads, which don’t contain as much acid as the bigger part of the plant.

The Myth: Play Dead During Bear Attacks

No one ever hopes to run into a bear during a leisurely walk in the woods, but it does happen. The general advice has always been to play dead, and never to run—after all, a grizzly bear can get up to speeds of 35 miles per hour, so it can definitely catch you.

When it comes to playing dead, however, that advice completely depends on the type of bear that’s actually near you.

If you come into contact with a grizzly bear or brown bear, it will probably only attack if it feels you are a threat to it or its cubs. If it hasn’t seen you yet or seems to be warning you to go away, back away as slowly as possible and then make your escape when you’re a good distance away from it.

If the bear actually makes contact with you, lay face down and keep your hands over the back of your neck until it backs off. If the bear is actually attacking or seems to be hunting you, you may eventually have to fight by hitting it in the face with whatever you can find.

However, it comes to a black bear attack, the answer is always to try and fight it off, not to lay down. Good luck.

The Myth: You Can Suck Venom Out of Snake Bite Wounds

This myth just seems like the kind of thing that someone had success with one time, and it became the go-to piece of advice for the situation. When someone gets bitten by a poisonous snake, the venom goes into their bloodstream immediately, no question.

By trying to suck the venom out of the bite, you’re not only adding bacteria to the wound, but you can easily get the venom into your own system, too.

If you or someone you’re with gets bitten by anything poisonous while out and about, it’s important to make sure their heart rate stays low. Panicking will only help the venom to make its way through the body faster, so you’ll need to help keep them calm while help arrives.

You should also keep the bitten area below heart level to slow the spread of venom in the bloodstream.

The Myth: Rubbing Frostbitten Skin Helps Warm Someone Up

Your first instinct when you see someone with frostbite is probably to get them warmed up as quickly as possible. However, the quick route is actually what’ll make them worse.

Sticking someone with frostbite into a hot tub or steaming bath can send them into shock, and even cause more damage to their skin. Rubbing the skin to warm it up with friction is also a big no-no—it can worsen tissue damage, or take off some of the skin in extreme cases.

Anyone who has mild areas of frostbite needs to be slowly warmed back up with blankets, heating pads on a low setting, or just laying down in a warm room. Get them checked out by a doctor afterward, though, especially if there’s extensive tissue damage or if feeling doesn’t come back to the affected area.

The Myth: If An Animal Can Eat It, So Can You

If you don’t have much knowledge when it comes to foraging, you might think that it’s safe to try anything you see an animal chowing down on. Though we can eat certain things they can, don’t let that be your guide on what’s safe.

The same way that bread isn’t actually great for ducks to eat, many of the wild berries and nuts that birds and squirrels munch on can be harmful to us.